Box for heat-treating metallic articles



C. B. CALLOMON.

BOX FOR HEAT TREATING METALLIC ARTICLES.

APPLICATION FILED OCT. 28. 1920.

1,3 7,23 Patented Aug. 9, 1921.

TI-*- i W21 follcwin is a full clear and exact descri b a a I 7 PATENT. entice.

,umreo stares cLARiiNc-n BERNARD CALLOMONQOF' SOUTH ORANGE, NEW JERsEY, AssIeNoR T0 DRIVER-HARRIS COMPANY, I-IAR-RTSON, NEW JERSEY, A. CORPORATION OF NEW JERSEY.

T 0 all whom it may concern:

Be it known that LCLARENGE B. GALLO- MON, a citizen of the United States,*res1d1ng at SouthOrange, county of Essex, State of New Jersey, have invented a certain new and useful Improvement in Boxes for Heat- Treating Metallic Articles, of which the close together in the furnace and still perm1t free circulation of heated'air 'andgases around them. It furtherhas for its object to producea box 'in'which the weight of material forming the box will be less than in Fig; 3 is a plan view of one box 'a similar point on the other side.

a rectangular box'of-the same capacity. It"

further has for its object to produce a box which will require less 'carburizing com pound when used as a carburizing boxithan' a rectangular box for a given number'of ar ticles to be treated. object to produce a box in which the time for producing a given result by heat treatment is reduced. It further has for its ob ject to produce a self-sealing box and oneof less height for a given capacity. The following is a description of a box embodying my invention, in which Figure 1 represents, partly in end view and partly in transverse section, a box embodying my invention piled upon others of the same sort;

Fig. 2 is a side elevation of one box and a portion of another similar box on which the first box rests; 7 body; and, Fig. 4 is a reverse plan view of the cover. Referring more particularly to the drawings, 1 is a box body having a wall 2 formed so as to have substantially true in ner and outer cylindrical surfaces starting near the mouth on one side and extending to The axes of these surfaces coincide in the center of the box. The hollow cylindrical body thus Specification of Letters Patent.

It further has for its Box FOR HEAT-TREATING ETAL IC enric es.

Patented Au .,9,{ 19 21.

Application filed .Octobery28, 1920. Se'ria1 No. 420,135.

formed is closed atits ends by end portions .3 formed integral therewith. The lower portlons of the two ends are provided with extensionsl having straight lower surfaces substantially in line with the plane tangent to the bottom of the box body; 4:"is a similar extension at the center of the box body.

The upperportions of the sid'esfare' provided 5 with vertical flanges -5,'which connect with internally projecting flanges 6 on theeiids so as to surround the-opening constituting the mouthof' the box; Thisopening is'a lat eral opening extending approximately from end portion to end portion, being an elongated openingwjnearly corresponding in length wlth the internal longitudinal'dimension of the-box. 1

.7 is "a coverof flatm'etal provided with a-down wardly projecting flange 8 extending around the- ,on'the tops of the extensions 5 and6.

same at aslight 'distance from; its edge so as to fit snugly within .the open-' In making such a box I use any metal 1 heretofore used for heat treatment'boxes ac-' cording to the temperature used inthe heat treating process. Thusthey may be made of cast iron for comparatively low t'emperm' tures. Forhigh'temperatures, I prefer to use. the nickel, chromium, iron alloys, such as specified in Patent No. 1,270,519, granted to J. C. Henderson on June 25, 1918.

A suitable box is about 47 inches long 7 and 137} inches in internal diameter, the walls and ends being about 5, ofaninch in thickness. The extensions forming the legs 4 and 4 are only of such width as will main-' tain the boxin upright position, their width,

being less than that of the cover.

The box may be made'by casting,.or the"? g cylindrical part maybe made of rolled sheet metal, the ends being cast thereon.

Boxes of'the shape described, on account of their cylindrical walls, practically eliminate the danger of warping when they are subjected to the necessary temperatures employed in the heat treatment.

pinging fiamewhich would set up bending stresses. A flame impinging on the'side of a box such asdescribed'would tend to cir- I v The stresses due to external heating conditions are equal:

culate at a tangent thereto and there could therefore be no direct flame action thereon.

Moreover, warping which might be caused by stresses setup inside a box, due to the generation of heat by the packing compound is also prevented, the circumferential stresses on the inside due from such causes being also equal at all points on the inside of the cylinder.

Furthermore, the boxes can be packed closer together in a furnace, as shown in Figs. 1 and 2, and still allow free circulation of heat around them on account of the spaces 9 which are necessarily present. Except for the small contact of the extensions 4 and 4 with the covers and the theoretical line of contact between a cover and the box body of a superimposed box, all portions of the box and cover are exposed to the hot air or gases of the furnace.

Furthermore, with a box of this tubular shape, the amount of metal necessary for producing a box of a given productive capacity is very much smaller than the amount necessary for boxes of shapes heretofore used. Furthermore, the tubular shape results in a very considerable saving of the carbonizing compound which it is necessary to use over what is necessary for a rectangular box, since there are no corners at the sides of the box which it is necessary to fill. The elimination of these corners, together with the resulting reduction in the carbon-v izing material also results in enabling the metallic parts to be heat treated to be closer to the internal surface of the box, with the result that they are heated more quickly and in this way the length of the heating period for a given hardening operation is reduced.

The height of the box is also reduced for abox of a given length and width, since it requires no legs or runners to permit the circulation of heat beneath the box.

The cover is so shaped that it is self-sealing, making it unnecessary to use any luting compound. I

The invention therefore attains the objects above stated.

As will be evident to those skilled in the art, my invention permits of various modi' fications without departing from the spirit thereof or the scope of the appended claims.

i/Vhat I claim is:

1. A box for heat treating metallic articles, comprising a hollow cylindrical body portion having an opening on one side con:

stituting the mouth of the box, said opening extending approximately the full length of said body portion, vertical end closing portions for said box body, and a cover for said box.

2. A box for heat treating metallic articles, comprising a hollow cylindrical body portion having an opening on one side constituting the mouth of the box, said opening extending approximately the full length of said body portion,vertical end closing p0rtions for said box, and a cover for said box, said box having on its bottom leg portions terminating substantially in a plane tangent to the bottom of said box.

3. A box for heat treating metallic articles, comprising a hollow cylindrical body portion having an opening on one side constituting the mouth of the box, said opening extending approximately the full length of said body portion, vertical end closing portions for said box body, and a cover for said box, said cover extending over said flanges and having a downward projection fitting said mouth.

CLARENCE BERNARD CALLOIWON. 

